SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587902f8fb4e4473494fe3cf6c23b8148da8be604512da90aa7c1562bcd63c6c' 
  AND token = '59QD/Jn6ay5vpa9akOotqIQwblmKzJF+o9WsGVkBs0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}